Viscoelastic surfactant as drift control agent in pesticide formulations

ABSTRACT

Dual function viscoelastic surfactants (VES) which, when used in a pesticide formulation, are capable of producing a spray pattern between the patterns formed by spraying water and an aqueous pesticide solution containing guar gum as a way to reduce the drifting of the small drops to unintended targets while providing enhanced efficacy to the pesticide.

FIELD OF THE INVENTION

The present invention relates to a dual function viscoelastic surfactant (VES) which, when used in a pesticide formulation, is capable of producing a spray pattern between the patterns formed by spraying water and an aqueous pesticide solution containing guar gum as a way to reduce the drifting of the small drops to unintended targets while providing enhanced efficacy to the pesticide.

BACKGROUND OF THE INVENTION

The drift of spray from pesticide applications can expose people, wildlife, and the environment to pesticide residues that can cause health and environmental effects and property damage.

Various alternatives have been proposed in an attempt to reduce the amount of drifting of small droplets during spraying of an aqueous pesticide solution. For example, high molecular weight water soluble polymers such as a guar gum, xanthan gum, polyacrylamide and other ethylenically unsaturated monomers have been used as drift control agents in the agricultural application. It has been generally accepted that polymers which give optimum spray drift control are either non-ionic (e.g., acrylamide homopolymer) or have relatively low anionic content (e.g. 5 to 30 wt. %) and also have relatively high intrinsic viscosity, for instance above 6 dl/g. Guar gum is the most widely used drift control agent in the current world market. Unfortunately, these polymers have various drawbacks. Their solutions tend to show irreversible lose of their utility due to the fact that high molecular weight polymers undergo mechanical degradation of the polymer chain. In addition, typically it takes a long time for the high molecular weight polymers to evenly disperse or dissolve in aqueous liquids which may lead to many large and undissolved particles that could plug the spraying nozzle. In addition, the polymer drift control agents perform only one task—to control drift of small droplets during spraying.

Spray pattern plays an important role in small droplets drifting. When water is sprayed, many small liquid droplets form a mist which easily drifts away with wind. When an aqueous spraying solution containing a guar gum is sprayed, the sprayed pattern is modified so that the number of small droplets is much reduced. Reduction of the number of small droplets increases the size of the droplets when the spray volume remains the same. In fact, the size increase in a typical spraying solution containing guar gum as the drift control agent is often too much so that there are a lot of coarse droplets which tend to bounce off the plant leave and be wasted. Over the years, researchers have found out that the optimum spray pattern has a droplet size distribution between 100-400 m.

There is a need to develop a surfactant based drift control agent capable of reducing the drifting of the small spraying drops as well as enhancing the efficacy of the pesticide without excessive large number of coarse droplets during spraying. Various surfactants are well known to enhance pesticide efficacy by modifying the surface tension of water leading to increased wetting, penetration, and absorption on the surfaces of targeted species.

U.S. Pat. No. 4,770,814 disclosed an anti-misting agent using a VES pair consisting of alkyl trimethyl quaternary surfactant and a organic acid as its counterion and a organic salt with the same ion. Example 1 (sample #2) in the document disclosed a herbicide composition containing 99.4% deionized water, 0.23% cetyltrimethylammonium salicylate, 0.27 sodium salicylate, and 0.1% 2,4-D acid herbicide. This composition was shown to reduce the number of small-sized droplets relative to the sample containing only water.

SUMMARY OF THE INVENTION

The present invention relates to a dual function viscoelastic surfactant (VES) which, when used in a pesticide formulation, is capable of producing a spray pattern between the patterns formed by spraying water and an aqueous pesticide solution containing guar gum. The VES are nitrogen containing surfactants known as alkoxylated alkyl quaternary surfactant, alkyl amine oxide including its alkoxylated derivatives, alkyl betaine including its alkoxylated derivatives, alkyl amidoamine (especially dimethylpropylamidoamine) including its alkoxylated derivatives, alkyl amidoamine (especially dimethylpropylamidoamine) quaternary surfactant including its alkoxylated derivatives, alkyl amidoamine (especially dimethylpropylamidoamine) oxide surfactant including its alkoxylated derivatives, and alkyl amidoamine (especially dimethylpropylamidoamine) betaine surfactant including its alkoxylated derivatives.

DETAILED DESCRIPTION OF THE INVENTION

The present invention generally relates to a composition and method for imparting shear stable anti-drifting properties to aqueous pesticidal formulations through the use of one or more VES. More specifically, the present invention relates to compositions comprising at least one nitrogen based VES in a pesticide formulation where the VES is capable of producing a spray pattern between the patterns formed by spraying water and spraying an aqueous pesticide solution containing guar gum with reduced number of small-sized droplets and coarse droplets size while providing enhanced efficacy to the pesticide.

The following classes of nitrogen containing VES are useful as drift control agents in pesticide formulations according to the invention.

where R is C12 to C22 linear or branched, saturated or unsaturated hydrocarbon group; AO is C1-C3 alkylene oxide; m=0-3; n=1-3; b=1-3; Z is nothing (or a pair of electron), C₁-C₄ alkyl, hydroxyl alkyl, oxygen, or CH₂COO; X⁻ is an suitable anion (N bears a positive charge in this case) or nothing when Z is nothing (or a pair of electron), a oxygen or CH₂COO;

where R is C12-C22 linear or branched, saturated or non-saturated hydrocarbon group; B=C2-C6 alkylene; p=0-5; V, D, Y, Z, and E independently is nothing (or a pair of electrons), H (hydrogen), C1-C4 alkyl, or a polyalkoxide group with 1 to 3 alkoxide units with the provisos that (1) V and D can not be both nothing at the same time and (2) the selection of Y, Z, and E only allows the end nitrogen atom to be tertiary or quaternary; X⁻ is a suitable anion(s).

where R is C12-C22 linear or branched, saturated or non-saturated hydrocarbon group; B=C2-C6 alkylene; p=0-5; W is H, CH₂COO, or CH₂CH₂OH; V′, Y′, Z′, D′, E′ independently is nothing (or a pair electron), H (hydrogen), C1-C4 alkyl, a polyalkoxide group with 1 to 3 alkoxide units, O (oxygen), CH₂COO, CH₂COO⁻M⁺ or CH₂CH₂COO⁻M⁺ where M is H, Na, K, Li, NH4, monoethanolamine, diethanolamine, triethanolamine, isopropylamine, dimethyamine, or dimethylamidopropylamine (DMAPA) with the provisos that (1) the structure contains at least one amideoxide, betaine, or iminopropinate group, (2) V′ and D′ can not be nothing at the same time, and (3) the selection of Y′, Z′, and E′ only allows the end nitrogen atom to be tertiary or quaternary.

The compositions of the invention can be prepared in the manner known to the skilled artisan, including but not limited to in-can and tank mix and application of the final formulation may be pre- or post-emergence. Post-emergence application results in particular advantages.

The VES drift control agent of the present invention can be added directly to a spray tank along with other ingredients. When used as a tank side additive, an effective amount of the drift control agent comprising at least one VES of the present invention is generally represented by weight concentrations of from 0.001% to 5.0%, in another embodiment from 0.01% to 1.0%. Likewise, when the VES of the present invention is used in a pesticide formulation (in-can), it is present at weight concentrations that will deliver from about 0.001% to 5.0% to the final use dilution, in another embodiment from about 0.01% to 1.0%, of the final use dilution.

Suitable herbicides include acetochlor, acifluorfen, aclonifen, alachlor, ametryn, amidosulfuron, aminopyralid, amitrole, anilofos, asulam, atrazine, azafenidin, azimsulfuron, benazolin, benfluralin, bensulfuron-methyl, bentazone, bifenox, binalafos, bispyribac-sodium, bromacil, bromoxynil, butachlor, butroxidim, cafenstrole, carbetamide, carfentrazone-ethyl, chloridazon, Chlorimuron-ethyl, chlorobromuron, chlorotoluron, chlorsulfuron, cinidon-ethyl, cinosulfuron, clethodim, Clomazone, Clopyralid, Cloransulam-methyl, Clorsulfuron, Cyanazine, Cycloate, Cyclosulfamuron, Cycloxydim, Dalapon, Desmedipham, Dicamba, Dichlobenil, Dichlormid, Diclosulam, Diflufenican, Dimefuron, Dimepipeate, Dimethachlor, Dimethenamid, Diquat, Diuron, Esprocarb, Ethalfluralin, Ethametsulfuron-methyl, Ethofumesate, Ethoxysulfuron, Fentrazamide, Flazasulfuron, Florasulam, Fluchloralin, Flufenacet, Flumetsulam, Flumioxazin, Fluometuron, Flupyrsulfuron-methyl, Flurochloridone, Fluroxypyr, Flurtamone, Fomesafen, Foramsulfuron, Glufosinate, Hexazinone, Imazamethabenz-m, Imazamox, mazapic, Imazapyr, Imazaquin, Imazethapyr, Imazosulfuron, Iodosulfuron, Ioxynil, Isoproturon, Isoxaben, Isoxaflutole, Lactofen, Lenacil, Linuron, Mefenacet, Mesosulfuron-Methyl, Mesotrione, Metamitron, Metazachlor, Methabenzthiazuron, Metobromuron, Metolachlor, Metosulam, Metoxuron, Metribuzin, Metsulfuron-methyl, Molinate, MSMA, Napropamide, Nicosulfuron, Norflurazon, Oryzalin, Oxadiargyl, Oxadiazon, Oxasulfuron, Oxyfluorfen, Paraquat, Pendimethalin, Phenmedipham, Picloram, Pretilachlor, Profoxydim, Prometryn, Propanil, Propisochlor, Propoxycarbazone, Propyzamide, Prosulfocarb, Prosulfuron, Pyraflufen-ethyl, Pyrazosulfuron, Pyridate, Pyrithiobac, Quinclorac, Quinmerac, Rimsulfuron, Sethoxydim, Simazine, S-Metolachlor, Sulcotrione, Sulfentrazone, Sulfosulfuron, Tebuthiuron, Tepraloxydim, Terbuthylazine, Terbutryn, Thifensulfuron-methyl, Thiobencarb, Tralkoxydim, Tri-allate, Triasulfuron, Tribenuron-methyl, Triclopyr, Trifloxysulfuron, Trifluralin, Triflusulfuron-methyl, Tritosulfuron, and mixtures and combinations thereof. Preferred herbicides are Acetochlor, Atrazine, Dicamba, Glufosinate, Paraquat, and mixtures and combinations thereof. More preferred herbicides are glyphosate, Atrazine, Dicamba, and Glufosinate and mixtures and combinations thereof. The most preferred herbicides are salts of glyphosate and glufosinate-ammonium. When the herbicide is an acid, it can be used in the acid form, though it is preferred that the herbicide be in the salt form selected from at least one of the group of an amine, lithium, sodium, ammonium or potassium. It shall be pointed out that when a pesticide appears in the text as a general name without specifying the counterions, it means both its acid form and salt form through out the specification.

Another embodiment of the present invention is a fungicide formulation having improved drift control comprising VES in accordance with the invention. Examples of suitable fungicides are:

Acibenzolar-S-methyl, aldimorph, amisulbrom, anilazine, azaconazole, azoxystrobin, benalaxyl, benodanil, benomyl, benthiavalicarb, binapacryl, biphenyl, bitertanol, blasticidin-S, boscalid, bromuconazole, bupirimate, captafol, captan, carbendazim, carboxin, carpropamid, chloroneb, to chlorothalonil, chlozolinate, copper, cyazofamid, cyflufenamid, cymoxanil, cyproconazole, cyprodinil, dichlofluanid, diclocymet, diclomezine, dicloran, diethofencarb, difenoconazole, diflumetorim, dimethirimol, dimethomorph, dimoxystrobin, diniconazole, dinocap, dithianon, dodemorph, dodine, edifenphos, enestrobin, epoxiconazole, etaconazole, ethaboxam, ethirimol, etridiazole, famoxadone, fenamidone, fenarimol, fenbuconazole, fenfuram, fenhexamid, fenoxanil, fenpiclonil, fenpropidin, fenpropimorph, fentin acetate, fentin chloride, fentin hydroxide, ferbam, ferimzone, fluazinam, fludioxonil, flumorph, fluopicolide, fluoxastrobin, fluquinconazole, flusilazole, flusulfamide, flutolanil, flutriafol, folpet, fosetyl-Al, fthalide, fuberidazole, furalaxyl, furametpyr, guazatine, hexaconazole, hymexazole, imazalil, imibenconazole, iminoctadine, iodocarb, ipconazole, iprobenfos (IBP), iprodione, iprovalicarb, isoprothiolane, isotianil, kasugamycin, kresoxim-methyl, laminarin, mancozeb, mandipropamid, maneb, material of biological, mepanipyrim, mepronil, meptyldinocap, metalaxyl, metalaxyl-M, metconazole, methasulfocarb, metiram, metominostrobin, metrafenone, mineral oils, organic oils, myclobutanil, naftifine, nuarimol, octhilinone, ofurace, origin, orysastrobin, oxadixyl, oxolinic acid, oxpoconazole, oxycarboxin, oxytetracycline, pefurazoate, penconazole, pencycuron, penthiopyrad, phophorous acid and, picoxystrobin, piperalin, polyoxin, potassium bicarbonate, probenazole, prochloraz, procymidone, propamocarb, propiconazole, propineb, proquinazid, prothiocarb, prothioconazole, pyraclostrobin, pyrazophos, pyribencarb, pyributicarb, pyrifenox, pyrimethanil, pyroquilon, quinoxyfen, quintozene (PCNB), salts, silthiofam, simeconazole, spiroxamine, streptomycin, sulphur, tebuconazole, teclofthalam, tecnazene (TCNB), terbinafine, tetraconazole, thiabendazole, thifluzami de, thiophanate, thiophanate-methyl, thiram, tiadinil, tolclofosmethyl, tolylfluanid, triadimefon, triadimenol, triazoxi de, tricyclazole, tridemorph, trifloxystrobin, triflumizole, triforine, triticonazole, validamycin, valiphenal, vinclozolin, zineb, ziram, and zoxamide, and mixtures and combinations thereof

Still another embodiment of the present invention is an insecticide formulation having improved drift control comprising VES in accordance with the invention. Examples of suitable insecticides are: kerosene or borax, botanicals or natural organic compounds (nicotine, pyrethrin, strychnine and rotenone), chorinated hydrocarbon (DDT, lindane, chlordane), organophosphates (malathion and diazinon), carbamates (carbaryl and propoxur), fumigants (naphthalene) and benzene (mothballs), synthetic pyrethroids, and mixtures and combinations thereof.

The above listings of specific pesticides are not intended to be inclusive of all possibilities.

Yet still another embodiment of the present invention is a mixture of any herbicide, fungicide, and insecticide selected form the above groups having improved drift control comprising VES in accordance with the invention.

The invention will now be illustrated by the following non-limiting examples.

EXAMPLE 1.

100 g of testing solution was prepared according to the composition of the following table. If the VES surfactant formed gel in water, heating (to ˜60-70 C) was used to facilitate dissolution. Mixing was with a magnetic bar until the sample totally dissolved (or evenly dispersed). Order of adding was not critical. Data was recorded in notebook 2207-71.

In the following table, C1 means component 1, C2 component 2 and C3 component 3. Appr means appearance, Ki viscosity cP means kinematic viscosity in centipoise, measured by a U-shape viscometer, model Cannon 100 Z858.

VES-2C was a experimental blend comprising about 51% erucyl dimethyl amidopropyl betaine,

DR-2000 was a commercial guar gum product used as drift control agent in agriculture, Ethoquad E/12 was erucyl 2-EO methyl chloride quaternary; Aromox APA-T was tallow dimethylamidopropyl amine (DMAPA), Arquad 16-29 was C16 trimethyl chloride quaternary (29% active in water), Arquad SV-60 was soya trimethyl chloride quaternary (60%), Arquad

APA-E E was 80% erucyl dimethyl amidopropyl betaine, Arquad 2HT-83E was ˜83% di-tallow dimethyl chloride quaternary, Arquad 2C-75 was 75% di-coco dimethyl chloride quaternary, and Roundup® Original was a commercial product from Monsanto containing isopropylamine salt of glyphosate and tallowamine ethoxylate.

Ki Surface Name of wt of wt of Name of wt of Name of wt of Visco tension C1 C1 Water C2 C2 C3 C3 Appr cP mN/m 1 99.9 VES-2C 0.1077 C 1.42 33.9 2 99.9 DR-2000 0.1008 H 3.41 45.03 Guar 3 99.9 Erucid 0.1054 I 34.13 amido betaine 4 99.9 Ethoquad 0.1154 C 0.98 37.2 E/12 5 99.9 Aromox 0.1065 C 1.02 32.54 APA-T 6 99.9 Arquad 0.1081 Na 0.02 C 2.07 33.07 16-29 salicylate 7 99.9 Arquad 0.1065 Na 0.02 C 2.27 32.81 SV-60 salicylate 8 99.9 Arquad 0.0985 C 0.98 40.47 APA-E E 9 99.9 Arquad 0.0999 H 1.38 33.57 2HT-83E 10 99.9 Arquad 0.1011 C 0.99 28.54 2C-75 11 62% IPA 1 98.9 VES-2C 0.0994 C 1.01 33.44 glyphosate 12 62% IPA 1 98.9 DR-2000 0.1009 H 3.52 47.47 glyphosate Guar 13 62% IPA 1 98.9 DR-2000 0.1008 Na 0.02 C 3.31 43.83 glyphosate Guar salicylate 14 62% IPA 1 98.9 DR-2000 0.1008 Na 0.02 C 3.45 glyphosate Guar salicylate 15 62% IPA 1 98.9 Erucid 0.1008 C 3.31 31.71 glyphosate amido betaine 16 62% IPA 1 98.9 Ethoquad 0.1052 C 0.98 36.98 glyphosate E/12 17 62% IPA 1 98.9 Ethoquad 0.1129 Na 0.02 C 2.01 32.37 glyphosate E/12 salicylate 18 62% IPA 1 98.9 Ethoquad 0.1129 Na 0.02 C 3.21 glyphosate E/12 salicylate 19 62% IPA 1 98.9 Aromox 0.0976 C 0.95 33 glyphosate APA-T 20 62% IPA 1 98.92 Arquad 0.0774 C 0.95 40.9 glyphosate 16-29 21 62% IPA 1 98.92 Arquad 0.0761 Na 0.02 C 1.06 31.59 glyphosate 16-29 salicylate 22 62% IPA 1 98.92 Arquad 0.0761 Na 0.02 C 0.98 glyphosate 16-29 salicylate 23 62% IPA 1 98.92 Arquad 0.771 C 0.96 40.25 glyphosate SV-60 24 62% IPA 1 98.92 Arquad 0.0871 Na 0.02 C 1.22 32.51 glyphosate SV-60 salicylate 25 62% IPA 1 98.9 VES-1 0.1095 glyphosate 26 62% IPA 1 98.9 Arquad 0.1048 C 1.01 38.9 glyphosate APA-E E 27 62% IPA 1 98.9 Arquad 0.0987 I glyphosate 2HT-83E 28 62% IPA 1 98.9 Arquad 0.0999 H 1.04 26.8 glyphosate 2C-75 29 62% IPA 1 98.9 Arquad 0.1064 Na 0.02 H 1.12 26.54 glyphosate 2C-75 salicylate 30 Roundup 1.52 98.38 VES-2C 0.114 C 1.05 38.59 Original 31 Roundup 1.52 98.38 DR-2000 0.1022 H 3.55 42.03 Original Guar 32 Roundup 1.52 98.38 Erucid 0.0963 C 0.86 35.17 Original amido betaine 33 Roundup 1.52 98.38 Ethoquad 0.0994 C 0.86 39.61 Original E/12 34 Roundup 1.52 98.38 Aromox 0.0972 C 1.01 37.37 Original APA-T 35 Roundup 1.52 98.4 Arquad 0.0835 C 1.01 41.47 Original 16-29 36 Roundup 1.52 98.4 Arquad 0.0817 C 0.99 40.22 Original SV-60 37 Roundup 1.52 98.38 VES-1 Original 38 Roundup 1.52 98.38 Arquad 0.113 C 0.98 40.49 Original APA-E E 39 Roundup 1.52 98.38 Arquad 0.1047 I Original 2HT-83E 40 Roundup 1.52 98.38 Arquad 0.1045 C 1.01 31.68 Original 2C-75 41 50% 1 98.9 VES-2C 0.1101 C 0.96 ammonium glyphosate 42 50% 1 98.9 DR-2000 0.0982 I ammonium Guar glyphosate 43 50% 1 98.9 Erucid 0.0979 I ammonium amido glyphosate betaine 44 50% 1 98.9 Ethoquad 0.1057 Na 0.02 C 3.29 ammonium E/12 salicylate glyphosate 45 50% 1 98.9 Aromox 0.0997 C 1.08 ammonium APA-T glyphosate 46 50% 1 98.92 Arquad 0.1119 Na 0.02 C 1.16 ammonium 16-29 salicylate glyphosate 47 50% 1 98.92 Arquad 0.0853 Na 0.02 C 1.26 ammonium SV-60 salicylate glyphosate 48 50% 1 98.9 Arquad 0.095 C 0.96 ammonium APA-E E glyphosate 49 50% 1 98.9 Arquad 0.1074 Na 0.02 I ammonium 2HT-83E salicylate glyphosate 50 50% 1 98.9 Arquad 0.0997 Na 0.02 H 0.95 ammonium 2C-75 salicylate glyphosate Surface tension measurements were also carried out at room temperature using the Kruss 12 tensiometer.

EXAMPLE 2 Drift Repeatability Study

C 1% IPA D B glyphosate 1% IPA A 1% IPA (62%) + 0.1% glyphosate 1% IPA glyphosate Ethoquad (62%) + 0.1% E glyphosate (62%) + 0.1% E/12 + 0.02% Erucyl DMAPA Water (62%) DR-200 Na salicylate betaine only 10 sec wt 114.3 115.1 108.4 105.3 1, g 10 sec wt 117.6 113.4 107.2 118.8* 2, g 10 sec wt 114.9 115.9 109.1 106.1 3, g 10 sec wt 110.2 112.5 110.6 105.8 4, g Average 114.25 114.225 108.825 105.7333333 Not wt, g measured Solution thin thin thick thick thin appearance Drift level High Small level Medium level Medium level High level- (some drift) - (some drift) - level- poor good good poor

Method: One gallon of each of the above samples (5 samples including water) was prepared. The water used was city tap water in all cases. Samples were prepared the day before testing to ensure that samples were solubilized.

Each sample was sprayed using the tub sprayer with the yellow nozzle (designated “XR teejet”). The spraying pressure used was 30 psi. The sample was prayed into a 5-gal plastic bucket for 10 seconds and the weight of the sprayed sample was recorded. Four replicates were made for each sample. The drift level was determined by observing the mist during 10 second spraying intervals.

The tub was cleaned by rinsing with tap water between samples.

The data in example 2 indicated that 1% IPA glyphosate (62%) (Sample A) and water (Sample E) had high level of drifting (a lot of mist). 1% IPA glyphosate (62%)+0.1% DR-200 (Sample B) gave lowest level of drifting (least mist). Samples containing VES surfactants (Sample C and D) gave intermediate (desired) drift level between the guar only sample (Sample B) and 1% IPA glyphosate (62%) sample (Sample A).

EXAMPLE 3

Drift observation with a hand-held Sprayer (data recorded in notebook 2207-97)

Name of wt of wt of Name of wt of Name of wt of Name of wt of Drift C1 C1 H2O C2 C2 C3 C3 C4 C4 Pattern 62% IPA 0.33 30 fine glyphosate 62% IPA 0.33 30 DR-2000 0.033 thin glyphosate Guar 62% IPA 0.33 30 DR-2000 0.033 Armeen 0.1 thin glyphosate Guar APA 2 30 DR-2000 0.033 KCl 0.06 thin Guar 62% IPA 0.33 30 DR-2000 0.01 fine glyphosate Guar 62% IPA 0.33 30 DR-2000 0.01 Ethoquad 0.1 T/F  glyphosate Guar E/12 62% IPA 0.33 30 DR-2000 0.01 VES 2C 0.1 T/>F glyphosate Guar 62% IPA 0.33 30 corn 0.1 fine glyphosate starch 62% IPA 0.33 30 DR-2000 0.02 >T/F   glyphosate Guar 62% IPA 0.33 30 DR-2000 0.01 NS 500 0.043 T/>F glyphosate Guar LQ 62% IPA 0.33 30 DR-2000 0.01 CO 360 0.051 T/>F glyphosate Guar 62% IPA 0.33 30 DR-2000 0.01 Arquad 0.077 T/>F glyphosate Guar APA E E 62% IPA 0.33 30 DR-2000 0.01 TSP-15 0.051 T/>F glyphosate Guar 62% IPA 0.33 30 DR-2000 0.01 corn 0.01 Ethoquad 0.1 T/>F glyphosate Guar starch E/12 62% IPA 0.33 30 DR-2000 0.01 corn 0.01 VES 2C 0.1 T/>F glyphosate Guar starch

Tests for drift were conducted using a hand-held sprayer (sprayer head cat. #30W8TS and sprayer bottle cat. #68WRTS). Test solutions were added to the bottle and the spray head was pumped several times with constant pressure until a consistent spray was produced.

The normal spray pattern with water appeared as a fine, broad pattern of mist (fine). Samples containing guar exhibited a different pattern, consisting of a thin, concentrated spray stream with almost no fine mist being observed (thin). Samples shown as T/F were a mix of the two patterns. “>F” means a very fine spray pattern was observed.

This method of spraying seemed sensitive and capable of picking up small changes in drift characteristics.

All samples containing guar contained small floating globules after initial mixing. Overnight, these globules settled to the bottom of the vial. We noticed that the spray pattern of the clear upper layer from the guar sample was the same as that of the original sprayed samples (thin). 

What is claimed is:
 1. A pesticidal composition comprising (A) a pesticide and (B) an amount of a drift control agent effective to reduce drifting of drops of the composition to unintended targets while providing enhanced efficacy to the pesticide, wherein said drift control agent is the only enhancer of pesticide efficacy in the composition, wherein said drift control agent comprises at least one nitrogen containing viscoelastic surfactant of the formula:

where R is C15 to C21 linear or branched, saturated or unsaturated hydrocarbon group; Z is O (oxygen), CH₂COO, or CH₃; and X⁻ is nothing when Z is O (oxygen) or CH₂COO and X⁻ is a suitable anion when Z is CH₃.
 2. The composition of claim 1 wherein said pesticide is selected from the group consisting of insecticides, fungicides, herbicides, and mixtures thereof.
 3. The composition of claim 2 wherein said herbicide does not contain 2,4-dichlorophenoxyacetic acid (“2,4-D”).
 4. The composition of claim 1 wherein said pesticide is a herbicide selected from the group consisting of glyphosate, dicamba, atrazine, paraquat, and mixtures thereof.
 5. The composition of any one of the preceding claims which additionally comprises at least one additional polymer selected from the group consisting of guar gum, xanthan gum, polyacrylamide and mixtures thereof.
 6. The composition of any one of the preceding claims wherein the viscoelastic surfactant is a C16-C22 dimethylpropylamidoamine oxide.
 7. The composition of any one of the preceding claims wherein the viscoelastic surfactant is a C16-C22 dimethylpropylamidoamine betaine.
 8. The composition of any one of the preceding claims wherein the viscoelastic surfactant is a methyl chloride quaternized C16-C22 dimethylpropylamidoamine.
 9. A method of reducing adverse drift in a pesticidal composition comprising a pesticide, said method comprising adding to said composition an amount of a drift control agent effective to reduce drifting of drops of the composition to unintended targets while providing enhanced efficacy to the pesticide, wherein said drift control agent is the only enhancer of pesticide efficacy in the composition, wherein said drift control agent comprises at least one nitrogen containing viscoelastic surfactant of the formula:

where R is C15 to C21 linear or branched, saturated or unsaturated hydrocarbon group; Z is O (oxygen), CH₂COO, or CH₃; and X⁻ is nothing when Z is O (oxygen) or CH₂COO and X⁻ is a suitable anion when Z is CH₃.
 10. The method of claim 9 wherein said pesticide is selected from the group consisting of an insecticide, fungicide, herbicide, and mixtures thereof.
 11. The method of claim 10 wherein said herbicide does not contain 2,4-dichlorophenoxyacetic acid (“2,4-D”).
 12. The method of claim 9 wherein said pesticide is a herbicide selected from the group consisting of glyphosate, dicamba, atrazine, paraquat, and mixtures thereof.
 13. A method of claim 9, wherein the drift control agent is added directly to a spray tank along with other ingredients of the pesticidal composition.
 14. A method of combatting pests with reduced drifting of a pesticidal composition employed for said combatting, said method comprising spraying on the pests or on an area from which it is desired to exclude such pests an effective amount of pesticidal composition according to claim
 1. 